Plumbing in the Home/shower valves

I am trying to fix the constant dripping from the shower valves, both hot and cold. They are American Standard from the 70`s, seperate valves for each. I took off handles and stem covers but the inside stem moves around freely. I am guessing that is where the leak is coming past the valve inside. Do i have to replace the whole thing since that piece wont come out to put new rings in.
Thnaks , Steve

Hi Steve
This should be a pretty straightforward operation. I think the problem is that you have only removed the packing gland nut and not the larger nut that holds the stem in place called a bonnet nut.
From your pictures, it appears that you will need to break away a bit more tile and grout/mortar to access these larger nuts. To remove these requires a special sin wall deep socket called a bonnet nut wrench. These are inexpensive and available at most hardware and big box stores for under 10 bucks usually. Once you unscrew the bonnet nut, the entire stem should come out with it. This will also provide access to the "rings" also called valve seats. Removing the valve seat also requires a special wrench that is also inexpensive. The Rings should also be replaced along with the stems. I am providing pictures. These pictures are not 100% accurate since the bonnet nut in this picture is protruding enough to use a conventional wrench on and the seat wrench is being used on a sink faucet but you get the idea.
Good Luck,
Dana

Dana Bostick

Expertise

Pretty much any residential plumbing questions. For "item specific" details such as a specific model of fixture, I will need to research and there may not be any useful information available.
Note: I live and work in Southern California. We do not, as a rule, use hot water or steam heating systems, oil fired boilers or private water wells so my knowledge in those areas is pretty limited. There are others here on AllExerts that can probably answer those questions better.